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.bashrc에서 에코 할 때 SCP가 작동하지 않습니까?

crosscheck 2020. 10. 30. 07:43
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.bashrc에서 에코 할 때 SCP가 작동하지 않습니까?


Fedora에 두 명의 사용자가 있습니다.

  1. 와니
  2. 뿌리 (아주 분명!)

사용자 Wani의 .bashrc 내용은 다음과 같습니다.

# .bashrc
echo "Hello"
# Source global definitions
if [ -f /etc/bashrc ]; then
    . /etc/bashrc
fi

# User specific aliases and functions

이제 루트에 로그인 한 후 다음 명령을 입력합니다.

[root@Dell Wani]# touch try.txt
[root@Dell Wani]# service sshd start
[root@Dell Wani]# scp try.txt Wani@localhost:~/
Wani@localhost's password: 
Hello
[root@Dell Wani]# 

이제 Wani에 로그인하고 다음을 입력합니다.

[Wani@Dell ~]$ cat try.txt
cat: try.txt: No such file or directory
[Wani@Dell ~]$ 

이제 다시 루트에 로그인하고 다음과 같은 명령을 입력합니다 -v.

[root@Dell Wani]# scp -v morph.log Wani@localhost:
Executing: program /usr/bin/ssh host localhost, user Wani, command scp -v -t -- .
OpenSSH_5.6p1, OpenSSL 1.0.0j-fips 10 May 2012
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to localhost [127.0.0.1] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: identity file /root/.ssh/id_rsa type -1
debug1: identity file /root/.ssh/id_rsa-cert type -1
debug1: identity file /root/.ssh/id_dsa type -1
debug1: identity file /root/.ssh/id_dsa-cert type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.6
debug1: match: OpenSSH_5.6 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.6
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-md5 none
debug1: kex: client->server aes128-ctr hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Host 'localhost' is known and matches the RSA host key.
debug1: Found key in /root/.ssh/known_hosts:2
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-     with-mic,password
debug1: Next authentication method: gssapi-keyex
debug1: No valid Key exchange context
debug1: Next authentication method: gssapi-with-mic
debug1: Unspecified GSS failure.  Minor code may provide more information
Credentials cache file '/tmp/krb5cc_0' not found

debug1: Unspecified GSS failure.  Minor code may provide more information
Credentials cache file '/tmp/krb5cc_0' not found

debug1: Unspecified GSS failure.  Minor code may provide more information


debug1: Unspecified GSS failure.  Minor code may provide more information


debug1: Next authentication method: publickey
debug1: Trying private key: /root/.ssh/id_rsa
debug1: Trying private key: /root/.ssh/id_dsa
debug1: Next authentication method: password
Wani@localhost's password: 
debug1: Authentication succeeded (password).
Authenticated to localhost ([127.0.0.1]:22).
debug1: channel 0: new [client-session]
debug1: Requesting no-more-sessions@openssh.com
debug1: Entering interactive session.
debug1: Sending environment.
debug1: Sending env XMODIFIERS = @im=none
debug1: Sending env LANG = en_US.UTF-8
debug1: Sending command: scp -v -t -- .
Hello
[root@Dell Wani]# debug1: client_input_channel_req: channel 0 rtype exit-status      reply      0
debug1: channel 0: free: client-session, nchannels 1
debug1: fd 0 clearing O_NONBLOCK
debug1: fd 1 clearing O_NONBLOCK
Transferred: sent 1664, received 1976 bytes, in 0.1 seconds
Bytes per second: sent 22961.5, received 27266.8
debug1: Exit status 0

(그리고 Enter 키를 누른 후)

[root@Dell Wani]# 

누구든지 여기서 정확히 무슨 일이 일어 났는지 밝힐 수 있습니까? 왜 파일이 ​​루트에서 Wani로 복사되지 않았습니까?


echoin a .bashrc사용 하면 stdin / stdout 채널을 통해 프로토콜 데이터를 볼 수 있으므로 중단 scp됩니다 scp. 이 문제에 대한 자세한 내용은 https://bugzilla.redhat.com/show_bug.cgi?id=20527참조 하십시오 .

사용 가능한 몇 가지 해결 방법이 있습니다.

  • '대화 형'플래그의 조건 (예 : case $- in *i*tripleee에서 제안한대로)
  • Use the tty utility to detect an interactive shell (e.g. if tty > /dev/null or if [ -t 0 ])
  • Check the value of $SSH_TTY

I suppose you should use whichever one works for you. I don't know what the best (most portable/most reliable) option is, unfortunately.


To add to nneonneo's options, you can also condition with the interactive flag with

if [[ $- =~ "i" ]]

which I think is possibly the clearest way in bash.


This works for me,
In .bashrc add first line as:

if [ -z "$PS1" ]; then
    return
fi

https://superuser.com/questions/690735/can-i-tell-if-im-in-an-scp-session-in-my-bashrc


The default Ubuntu .bashrc contains the following snippet which already takes care of the problem:

# If not running interactively, don't do anything
case $- in
    *i*) ;;
    *) return;;
esac

In .bashrc, use STDERR as output instead:

echo "# Important Notice" >&2

Update: do not use it! We had an issue recently that a (closed source) tool failed due to an echo to STDERR in .bashrc. The tool (using rcp) expected no output at all, neither on STDOUT nor STDERR. And it stuck when it got the echo. Lesson learned: make separate accounts for humans and for machines (scripts), or just stop tattling via .bashrc.


The most portable way of testing for an interactive shell seems to be:

test -t 0
if [ $? -eq 0 ]
then
    # interactive
    ;
else
    # non-interactive
    ;
fi

nneonneo's solution worked for me as well. But since my default shell is TCSH, I had to slightly edit the fix as follows (in .tcshrc):

if ( $?SSH_TTY ) then
    exec /bin/bash
endif

Just thought I would share for everyone's benefit.


if [ 0 -eq $(shopt -q login_shell; echo $?) ]; then
  echo "do something?"
fi

Source


If you're on Red Hat Enterprise Linux (RHEL) or variant, drop a script that does the echo, or whatever you want, into /etc/profile.d/


If you want echo statements as well, the from @Blauhirn's answer, you can keep placing your echo statement/s after the case condition.

case $- in
    *i*) ;;
    *) return;;
esac

echo "Your Greeting/Warning Message/s here!"

참고URL : https://stackoverflow.com/questions/12440287/scp-doesnt-work-when-echo-in-bashrc

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